There are different types of inhalers on the market. A pressurized Metered Dose Inhaler (pMDI) releases a fixed dose of substance in aerosol form. A powder inhaler generally releases a dose of powdered substance entrained in an air stream. In a powder inhaler the powder may be provided in a bulk container of the inhaler from which doses of powder are metered for dispensing. As an alternative to a bulk container, powder inhalers may comprise a single compartment or a plurality of compartments for containing discrete doses of powdered substance. Such compartments may take the form of sealed blisters in a blister pack, a cavities-containing strip joined to a sealing strip or other suitable forms.
There are different solutions to opening compartments containing discrete doses of powder. WO 01/72605 discloses different embodiments of a dose strip for use with a powder inhaler. Various opening mechanisms are disclosed. For instance, in FIG. 4 a lid strip covers spaced apart blisters. Lid tabs are attached to the lid strip over each blister. A peel strip is joined to each lid tab. Pulling of the peel strip opens the blisters. In FIG. 22 of WO 01/72605 a dose strip comprises a number of blisters containing pharmaceutical powder. Each blister is connected to a respective plunger. A blister is opened by a slider having a wedge that engages a slot on the plunger. The wedge pulls the plunger down, breaking the seal and releasing pharmaceutical powder into a flow path, for inhalation.